What Is the Forward Error Correction in Satellite Communication?

When the fans are using the satellite terminal to receive satellite signal, they will see the word of FEC frequently. FEC is short for Forward Error Correction. It is the method used to improve the reliability of data communication. When an error is found in the unidirectional signal path, the receiver will not have the authority of asking for data transmission again. However, FEC uses the data itself to prevent this problem when great amount of data needs to be transmitted.
FEC is one of the significant parameters of the satellite receiver. In some early digital receivers, the FEC parameter has to be typed in by users. As the process rate of the CPU of digital receivers improves, today's digital satellite receiver can measure the FEC parameter automatically, thus users don't have to type in the parameter any more. This likes the improvement in the process of searching channels. Today's satellite receivers can search can search the channels automatically while the earlier machines have to type in the parameters. Then, what is FEC used for?
As we all know, the digital programs have much purer colors and much sharper vision effect than the analog programs. The picture of the digital program won't have the interference, too. These advantages are just owing to the perfect anti - interference characteristic of digital signal. In the digital signals, we put in layers of error correction codes in order to prevent the mutation of the signal caused by other signal's interference. This is because the digital signal is very sensitive in the decoding progress. It may not be able to decode just because of a little flaw in the signal. So the signal's affluent playing is also due to the setting of error correction code. In all kinds of error correction codes, the FEC is a very significant anti - interference algorithm. Using it will improve the reliability of satellite signal a lot.
In order to understand the FEC code, let's have a look at the following analogy. If the ES stream is the raw material of the factory, the PES is the raw products and the TS stream is the product with a package. In the transformation of PES to TS, CPU adds the FEC code. In the DVB - S standard, there are 1/2, 2/3, 3/4, 5/6 and 7/8 five types of rate of FEC code in the signal stream. For example, 7/8 means that in the TS stream, 7/8 of the data is the video and audio information while the another 1/8 data is used to protect the information. This proportion of data is the FEC code. The TV signal uses the 2/3 rate.



Find the modern artist paintings &Angels oilpainting for your every important occassionChanel Coco Bags

Read more »

Posted in: Biotechnology

Science Research like Science fiction

Could there have been two satellites of the Earth, and a star shines now in our night sky, the other a little bit smaller. Scientists believe that, when two conflicts, some of the material can his sister to absorb satellite of the moon.
According to a new theory proposed that maybe used to two satellites of the Earth, but now that we had during the night also a small satellite of the Earth.
Back in the Highlands of the Moon, latest theory indicating that it was the slow-speed collision between two satellites led to this result at. Due to the small satellite material accumulated Highlands is in the back of the Moon, formed.
According to the modern Detektionsergebnisse, a side of the Moon faces the Earth and back again to the ground conditions are completely different. With a view on the main site on the side of the Earth is flat plains, while the back side of the Earth is mostly Highlands and mountains and has thick shells months much.
Trying to explain a variety of theories scientists previously, this asymmetry of the Moon shows, increases. What a mainstream view, that redesign of the Lunar crust is the tidal forces, and formed this asymmetry. But this is to "crash said:" new theory of effect, said the rule than the formation of the Moon explain based.
Many scientists believe, was born on the Moon formation of impact event: in the early solar system, a Mars met great object of the Earth, a large number of substances injects these deposits from orbit, it is because of gravity, gradually condensed and aggregation, eventually forming the moon. Scientists believe the formation of a second satellite, the Moon in Earth orbit for tens of millions of years was relatively small.
After this article was published in the near future the description of the work in the journal nature, the collision between two satellites is relatively slow, so slow the effects of overflow caused no massive crater, or a massive lava. A thick shell form substances produced in contrast to this that most impact in the occurrence and the impact of the side are stacked, months. This theory may also explain causes of a large number of mountain and highland regions on the far side of moon.
First author papers, in addition to the University of California, Santa Cruz, said Erik Asphaug: "our model can be very well coordinated and theory of the origin of the Moon, the impact to the impact of the theory of the Moon, is expected after the Moon was part of should be maintained debris material which provides the Foundation for our new theory on the Earth's orbit." And today we knew such a stability theory of system dynamics, condensing time of Moon and moon rocks from match data. "
Also from the University of California, Santa Cruz and his colleague Francis Nimmo (Francis Nomo) Professor a the proposed theory which is tidal distortion, he said: "both sides of the Moon shows significant geological characteristics were plaguing the profession, since the beginning of the space age, is its importance only by the origin of the moon itself".
He said: "the theory of Eric is impressive that he successfully the two topics linked maybe spray in substance in the collision, that the Moon further formed and finally began in the area fall back on the lunar surface in gravity, to form that we see." Today were two significant differences in hemisphere of the moon. "
Alone due to the lack of suitable data, it is not possible to determine which of the two statements in a more realistic.


notebook-battery.us is one of the best online notebook battery shop for US, which offer discount HP Pavilion dv6000 battery, MINOLTA NP-200 Battery and IBM ThinkPad T60 battery
Cheap, Save, Brand New, 100% OEM Compatible
One Year Warranty and 30-Day money back guarantee!!
Battery manufacturer online wholesale and retail

Read more »

Posted in: Biotechnology

What Is the Forward Error Correction in Satellite Communication?

When the fans are using the satellite terminal to receive satellite signal, they will see the word of FEC frequently. FEC is short for Forward Error Correction. It is the method used to improve the reliability of data communication. When an error is found in the unidirectional signal path, the receiver will not have the authority of asking for data transmission again. However, FEC uses the data itself to prevent this problem when great amount of data needs to be transmitted.
FEC is one of the significant parameters of the satellite receiver. In some early digital receivers, the FEC parameter has to be typed in by users. As the process rate of the CPU of digital receivers improves, today's digital satellite receiver can measure the FEC parameter automatically, thus users don't have to type in the parameter any more. This likes the improvement in the process of searching channels. Today's satellite receivers can search can search the channels automatically while the earlier machines have to type in the parameters. Then, what is FEC used for?
As we all know, the digital programs have much purer colors and much sharper vision effect than the analog programs. The picture of the digital program won't have the interference, too. These advantages are just owing to the perfect anti - interference characteristic of digital signal. In the digital signals, we put in layers of error correction codes in order to prevent the mutation of the signal caused by other signal's interference. This is because the digital signal is very sensitive in the decoding progress. It may not be able to decode just because of a little flaw in the signal. So the signal's affluent playing is also due to the setting of error correction code. In all kinds of error correction codes, the FEC is a very significant anti - interference algorithm. Using it will improve the reliability of satellite signal a lot.
In order to understand the FEC code, let's have a look at the following analogy. If the ES stream is the raw material of the factory, the PES is the raw products and the TS stream is the product with a package. In the transformation of PES to TS, CPU adds the FEC code. In the DVB - S standard, there are 1/2, 2/3, 3/4, 5/6 and 7/8 five types of rate of FEC code in the signal stream. For example, 7/8 means that in the TS stream, 7/8 of the data is the video and audio information while the another 1/8 data is used to protect the information. This proportion of data is the FEC code. The TV signal uses the 2/3 rate.



Find the modern artist paintings &Angels oilpainting for your every important occassionChanel Coco Bags

Read more »

Posted in: Biotechnology